Amirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220A high resolution finite volume scheme with a voronoi mesh for dam break simulationA high resolution finite volume scheme with a voronoi mesh for dam break simulation1939710.22060/ceej.2015.397FAHamid RezaVosoughifarHamidrezaJalalpour BarfroushPh.D. Studnet, Department of Civil Engineering, Science and Research Branch, Tehran, IranSeyedeh MonaTabandehPh.D. Student, Department of Civil Engineering, Science and Research Branch, Tehran, IranJournal Article20110117A high resolution finite volume method for solving the shallow water equations with voronoi mesh is developed applying MATLAB software in this paper. The scheme is formally uniformly second order accurate and satisfies maximum principles. The model is verified by comparing the model output with condition of anti-symmetric and circular dam break with documented results. For more investigation we utilized SPSS statistical software. Very good agreement has been achieved in the verification phase. It can be considered as an efficient implement for the computation of shallow water problems, especially concerning those having discontinuities. A simple example of the collapse of water supply reservoir in a valley is used to demonstrate the capability of the model. The presented model is able to resolving shocks, handling, complex geometry, including the influence of steep bed slopes.A high resolution finite volume method for solving the shallow water equations with voronoi mesh is developed applying MATLAB software in this paper. The scheme is formally uniformly second order accurate and satisfies maximum principles. The model is verified by comparing the model output with condition of anti-symmetric and circular dam break with documented results. For more investigation we utilized SPSS statistical software. Very good agreement has been achieved in the verification phase. It can be considered as an efficient implement for the computation of shallow water problems, especially concerning those having discontinuities. A simple example of the collapse of water supply reservoir in a valley is used to demonstrate the capability of the model. The presented model is able to resolving shocks, handling, complex geometry, including the influence of steep bed slopes.https://ceej.aut.ac.ir/article_397_e46de7e1bcaaced9a54f1e9d0d2f800d.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Effect of Four Iranian Natural Pozzolans on Concrete Durability Against Sulfate AttackEffect of Four Iranian Natural Pozzolans on Concrete Durability Against Sulfate Attack111739610.22060/ceej.2015.396FAAliakbarRamezanianpourProfessor, Department of Civil and Environmental Engineering, Amirkabir University of TechnologySeyyed SajjadMirvaladM.Sc. Student, Department of Civil and Environmental Engineering, Amirkabir University of TechnologyEhsanAramounM.Sc. Student, Department of Civil and Environmental Engineering, Amirkabir University of TechnologyMansourPeydayeshLecturer, Department of Civil and Environmental Engineering, Amirkabir University of TechnologyJournal Article20150530Sulfate attack is one of the most important problems concerning the durability of concrete structures. Natural pozzolans are the natural mineral admixtures which can improve concrete durability against sulfate attack. In this paper, the sulfate resistance of concrete and mortar samples made from ordinary Portland cement containing three different portions of four types of natural pozzolans (Eskandan Pumice, Khash Pumice, Abyek Tuff and Jajrood Trass) was studied. Strength reductions and mass changes of the concrete samples, immersed in sodium sulfate solution, as well as the expansion of mortar prisms, immersed in sodium and magnesium sulfate solutions, were monitored. It was observed that the resistance of mixtures containing natural pozzolans was higher against both sodium sulfate and magnesium sulfate attacks compared to the reference cement.Sulfate attack is one of the most important problems concerning the durability of concrete structures. Natural pozzolans are the natural mineral admixtures which can improve concrete durability against sulfate attack. In this paper, the sulfate resistance of concrete and mortar samples made from ordinary Portland cement containing three different portions of four types of natural pozzolans (Eskandan Pumice, Khash Pumice, Abyek Tuff and Jajrood Trass) was studied. Strength reductions and mass changes of the concrete samples, immersed in sodium sulfate solution, as well as the expansion of mortar prisms, immersed in sodium and magnesium sulfate solutions, were monitored. It was observed that the resistance of mixtures containing natural pozzolans was higher against both sodium sulfate and magnesium sulfate attacks compared to the reference cement.https://ceej.aut.ac.ir/article_396_f8c1f23d6a8d8d7904fc0ea8e066b3bb.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Study of Stiffened Central Panel Between Two Openings in Steel Plate Shear Walls with StiffenersStudy of Stiffened Central Panel Between Two Openings in Steel Plate Shear Walls with Stiffeners192838110.22060/ceej.2015.381FASaeidSabouriProfessor, Department of Civil Engineering, Khaje Nasir Toosi University of Technology0000-0002-8047-4980ElnazAhouriM.Sc. Student, Department of Civil Engineering, Khaje Nasir Toosi University of TechnologyJournal Article20110531The performance of central panel in dual-opening steel shear walls has been studied using the simple beam model, which its behavior depends on "height to width" ratio.Central panel has been made of bilateral stiffeners on both sides of the web plate. Now the central panel together with extreme stiffeners is comparable to a steel shear wall by itself. It is necessary for the cross-sectional area of the stiffeners to meet minimum requirements to force the ideal shear yielding of the central panel rather than flexural yielding of side stiffeners.Obviously, the "height to width" ratio of the central panel has been studied as a major factor in predicting its behavior. ABAQUS is the analytical tool used in the paper. It has also been concluded that the proper ratio selected for the central panel would result it to behave in a dominant shear mode.The performance of central panel in dual-opening steel shear walls has been studied using the simple beam model, which its behavior depends on "height to width" ratio.Central panel has been made of bilateral stiffeners on both sides of the web plate. Now the central panel together with extreme stiffeners is comparable to a steel shear wall by itself. It is necessary for the cross-sectional area of the stiffeners to meet minimum requirements to force the ideal shear yielding of the central panel rather than flexural yielding of side stiffeners.Obviously, the "height to width" ratio of the central panel has been studied as a major factor in predicting its behavior. ABAQUS is the analytical tool used in the paper. It has also been concluded that the proper ratio selected for the central panel would result it to behave in a dominant shear mode.https://ceej.aut.ac.ir/article_381_00ec53c4682d36f5c4359f4ae7bd7ba1.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Investigating effect of the preprocessing of the data on the accuracy of the modeling solid waste generation through ANNsInvestigating effect of the preprocessing of the data on the accuracy of the modeling solid waste generation through ANNs293738210.22060/ceej.2015.382FAMalihehFalahnezhadPh.D. Student, Department of Civil and Environmental Engineering, Tehran UniversityMohammad AliAbdoliProfessor, Department of Civil and Environmental Engineering, Tehran University0000-0002-0158-4891Journal Article20110703Waste generation in today industries is a serious problem. Waste generation from the production stage to the final disposal is an inevitable issue. Development of the cities and the industrialization causes the everyday increasing in solid waste generation. Therefore, knowing the waste values is an essential tool for solid waste management systems. In this research, artificial neural network is used as a financial tool for modeling solid waste generation in Mashhad. For this purpose, first, some pre-processing on the dependent and independent variables are done and the effect of this procedure on the accuracy of the model is investigated. Research findings clearly indicate that by using some preprocessing on the input data accurate results can be obtained. Three different conditions have been evaluated and the best one is selected which contains logarithm, trend removing and standardizing. The selected network has two hidden layers with five neurons in each one. Network performance parameters are MAPE, MSE and R2 that equals to 0.06, 0.46 and 0.86 respectively.Waste generation in today industries is a serious problem. Waste generation from the production stage to the final disposal is an inevitable issue. Development of the cities and the industrialization causes the everyday increasing in solid waste generation. Therefore, knowing the waste values is an essential tool for solid waste management systems. In this research, artificial neural network is used as a financial tool for modeling solid waste generation in Mashhad. For this purpose, first, some pre-processing on the dependent and independent variables are done and the effect of this procedure on the accuracy of the model is investigated. Research findings clearly indicate that by using some preprocessing on the input data accurate results can be obtained. Three different conditions have been evaluated and the best one is selected which contains logarithm, trend removing and standardizing. The selected network has two hidden layers with five neurons in each one. Network performance parameters are MAPE, MSE and R2 that equals to 0.06, 0.46 and 0.86 respectively.https://ceej.aut.ac.ir/article_382_4f6ffe13a5d75b2d6a3923922b3922e5.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Vertical expanding of landfill with considering its componentVertical expanding of landfill with considering its component394638310.22060/ceej.2015.383FANaderShariatmadariProfessor, School of Civil Engineering, Iran University of Science and Technology, Tehran, IranHamid RezaRazeghiAssistant Professor, School of Civil Engineering, Iran University of Science and Technology, Tehran, IranAhmadNayebiAssistant Professor, School of Civil Engineering, Iran University of Science and Technology, Tehran, IranMohammad HosseinHamzeie TehraniM.Sc. Student, School of Civil Engineering, Iran University of Science and Technology, Tehran, IranJournal Article20110613Shear strength of landfill municipal solid waste (MSW) is a more important topic in landfill stability investigation. Impressibility of this material from the temperature and humidity regarding to its early component cause that this material suffering much change in its shape. This variation with filling condition such as prime compression and soil increasing for daily and monthly cover change structure of MSW; so the fresh samples or primary component have not enough indication to define the problem. In this paper, large-scale direct shear tests were performed on the real samples with different age and different percent of soil obtained from Alborz landfill in Qom city to investigate shear strength of materials in existing landfill and to expand the landfill. Other parameters such as overconsolidation and plastic content have analyzed. The results shows that shear strength have decreased with increasing in waste age and plastic content. In addition, with changing in soil amount to optimum percent shear resistance increased and then decreased. Overconsolidation without changing in compaction effort has mutated the mobilization of shear strength.Shear strength of landfill municipal solid waste (MSW) is a more important topic in landfill stability investigation. Impressibility of this material from the temperature and humidity regarding to its early component cause that this material suffering much change in its shape. This variation with filling condition such as prime compression and soil increasing for daily and monthly cover change structure of MSW; so the fresh samples or primary component have not enough indication to define the problem. In this paper, large-scale direct shear tests were performed on the real samples with different age and different percent of soil obtained from Alborz landfill in Qom city to investigate shear strength of materials in existing landfill and to expand the landfill. Other parameters such as overconsolidation and plastic content have analyzed. The results shows that shear strength have decreased with increasing in waste age and plastic content. In addition, with changing in soil amount to optimum percent shear resistance increased and then decreased. Overconsolidation without changing in compaction effort has mutated the mobilization of shear strength.https://ceej.aut.ac.ir/article_383_beed13602b9b0e6ecb5b568ff5058f07.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220برآورد مقاومت نهایی یک پل قوسی بتنی غیرمسلح بر پایه نتایج محدود از تست بارگذاریبرآورد مقاومت نهایی یک پل قوسی بتنی غیرمسلح بر پایه نتایج محدود از تست بارگذاری475638410.22060/ceej.2015.384FAMohammad S.MarefatProfessor, School of Civil & Environmental Engineering, Tehran University, Tehran, IranMahdiYazdaniPh.D. Student, School of Civil & Environmental Engineering, Tarbiat Modares University, Tehran, IranShervanAtaeiAssistant Professor, School of Railway Engineering, Iran University of Science & Technology, Tehran, IranJournal Article20110711https://ceej.aut.ac.ir/article_384_0584ce565c824b7b7f50282d9a19945b.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Experimental study of concrete hinge connections with usual detailsExperimental study of concrete hinge connections with usual details576538510.22060/ceej.2015.385FAMajidMohammadiAssistant Professor, International Institute of Earthquake Engineering and Seismology, Tehran, I.R. Iran,0000-0003-2253-978XَAminMohammadiM.Sc. Student, Science and Research University, Tehran, I.R. IranJournal Article20110801Applying hinge connection in concrete building can sometimes decrease element sizes and improve seismic behavior of the structure. Despite of many details for such connections in special structures such as bridges, there is not any detail, accepted by both scientists and engineers, for hinges in regular concrete buildings. The existing details, in which the longitudinal reinforced bars cross each other at the center of the section, have not been verified well by experimental tests, therefore, they are not applied in practical projects. In this study two details, proposed for hinge connections are experimentally studied. In this regard, three cantilever concrete beam specimens with different connections were constructed and loaded by displacement-controlled loading. The first specimen had rigid connection that was used as a reference to be compared with other specimens. Both the second and third specimens had crossed reinforcements at the hinge part; however, the last one was also equipped with two grooves at the top and bottom of the section. <br />Moment- rotation diagrams of the specimens were compared to find their connection rigidity. The results show that connections with crossed reinforcement with or without grooves cannot be considered for hinge connections, for their brittle behaviors and considerable bending strengths.Applying hinge connection in concrete building can sometimes decrease element sizes and improve seismic behavior of the structure. Despite of many details for such connections in special structures such as bridges, there is not any detail, accepted by both scientists and engineers, for hinges in regular concrete buildings. The existing details, in which the longitudinal reinforced bars cross each other at the center of the section, have not been verified well by experimental tests, therefore, they are not applied in practical projects. In this study two details, proposed for hinge connections are experimentally studied. In this regard, three cantilever concrete beam specimens with different connections were constructed and loaded by displacement-controlled loading. The first specimen had rigid connection that was used as a reference to be compared with other specimens. Both the second and third specimens had crossed reinforcements at the hinge part; however, the last one was also equipped with two grooves at the top and bottom of the section. <br />Moment- rotation diagrams of the specimens were compared to find their connection rigidity. The results show that connections with crossed reinforcement with or without grooves cannot be considered for hinge connections, for their brittle behaviors and considerable bending strengths.https://ceej.aut.ac.ir/article_385_dc912a253d1e9ba40e2c597ed2376640.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220مقایسهی نتایج تحلیل عددی وآزمایشگاهی مقاومت بیرونکشش (Pull-Out) ژئوگرید و مهار- شبکه (Grid-Anchor) محصور شده توسط لایهیمقایسهی نتایج تحلیل عددی وآزمایشگاهی مقاومت بیرونکشش (Pull-Out) ژئوگرید و مهار- شبکه (Grid-Anchor) محصور شده توسط لایهی677838610.22060/ceej.2015.386FANazaninSohrabiM.Sc. Student, Department of Civil and Environmental Engineering, Shiraz University, IranNaderHatafProfessor, Department of Civil and Environmental Engineering, Shiraz University, IranJournal Article20111106The pull- out strength of the reinforcement has a significant role on the function of the most reinforced soil structures. Since the coarse grain soils have a better interaction with the reinforcement, they are mostly used in these structures. In most situations, we have to transfer these granular soils from the borrow area, usually far from the site of the project. This will impose a considerable amount of cost to the project. In this research, it is trying to use just a thin layer of coarse grain soil for surrounding the reinforcements. This is because of the important role of the pull- out strength on determining the kind of the reinforcements. From this point of view, in this paper, the results of the pull- out experiments conducted on an ordinary geogrid and an innovative reinforcement, that is named Grid- Anchor, are presented. While just a layer of coarse grain soil, with the selected thicknesses, is surrounding the reinforcement, the remained volume is replaced with the fine grain soils. Furthermore, the numerical analysis for these experiments is conducted using the finite element code, Plaxis 3D Tunnel. The numerical and experimental results indicate the efficiency of the cited method for cutting the expenses while keeping the function of the reinforced soil.The pull- out strength of the reinforcement has a significant role on the function of the most reinforced soil structures. Since the coarse grain soils have a better interaction with the reinforcement, they are mostly used in these structures. In most situations, we have to transfer these granular soils from the borrow area, usually far from the site of the project. This will impose a considerable amount of cost to the project. In this research, it is trying to use just a thin layer of coarse grain soil for surrounding the reinforcements. This is because of the important role of the pull- out strength on determining the kind of the reinforcements. From this point of view, in this paper, the results of the pull- out experiments conducted on an ordinary geogrid and an innovative reinforcement, that is named Grid- Anchor, are presented. While just a layer of coarse grain soil, with the selected thicknesses, is surrounding the reinforcement, the remained volume is replaced with the fine grain soils. Furthermore, the numerical analysis for these experiments is conducted using the finite element code, Plaxis 3D Tunnel. The numerical and experimental results indicate the efficiency of the cited method for cutting the expenses while keeping the function of the reinforced soil.https://ceej.aut.ac.ir/article_386_39461a19e9eddfb385ea76b26521ea48.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Bus Network Design Considering Transfer StationsBus Network Design Considering Transfer Stations799038710.22060/ceej.2015.387FAAfshinShariat MohaymanyAssociate Professor, Iran University of Science and TechnologyMajidShalforoushM.Sc. Student, Iran University of Science and TechnologyJournal Article20120314ABSTRACT <br />Bus network design is the first step in urban transportation planning process, and due to its influence on the consequent steps, such as timetabling, vehicle scheduling and crew scheduling, this step plays an important role in the process of transportation planning. One of the important issues in transit network design is locating transfer points. However, in the previous studies this issue was not considered, and it has been only paid attention to optimizing parameters such as travel time. This study is focused on defining the location of transfer points, as a result of transit network design, such that transfers are performed in points with higher capacities. Applying the genetic algorithm, the presented methodology is implemented on a virtual network, and the results showed that considering transfer constraint affects defining the location of transfer points.ABSTRACT <br />Bus network design is the first step in urban transportation planning process, and due to its influence on the consequent steps, such as timetabling, vehicle scheduling and crew scheduling, this step plays an important role in the process of transportation planning. One of the important issues in transit network design is locating transfer points. However, in the previous studies this issue was not considered, and it has been only paid attention to optimizing parameters such as travel time. This study is focused on defining the location of transfer points, as a result of transit network design, such that transfers are performed in points with higher capacities. Applying the genetic algorithm, the presented methodology is implemented on a virtual network, and the results showed that considering transfer constraint affects defining the location of transfer points.https://ceej.aut.ac.ir/article_387_8efb100a295c0c690931222ff4467bb8.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Effects of Joints Spacing on Static Bearing Capacity of Rock Foundations in the case of Punching FailureEffects of Joints Spacing on Static Bearing Capacity of Rock Foundations in the case of Punching Failure9110038810.22060/ceej.2015.388FAMeysamImaniPh.D. Student, Department of Civil & Environmental Engineering, Amirkabir University of Technology0000-0003-1449-5262AhmadFahimifarProfessor, Department of Civil & Environmental Engineering, Amirkabir University of Technology0000-0002-9397-6269MostafaSharifzadehAssociate Professor, Department of Mining & Metallurgical Engineering, Amirkabir University of TechnologyJournal Article20120407In this paper, using distinct element method, static bearing capacity of rock foundations containing one, two and three joint sets is investigated in the case of punching failure. The effect of joints spacing is incorporated to the analyses using a dimensionless factor, named spacing ratio (SR). Different values for SR are selected and variation of the bearing capacity versus SR is monitored. Then, the magnitude of SR in which the bearing capacity does not change significantly, is determined. The findings show that for SR<30, increasing the SR results in decreasing the bearing capacity, while for SR>30, the joints spacing do not affect the bearing capacity, significantly. Hence, SR=30 can be used as a criterion for analysis of rock foundations either as an equivalent continuum or a discontinuous medium. Using this criterion will tend to greatly reduce the time required for the bearing capacity analysis of rock foundations.In this paper, using distinct element method, static bearing capacity of rock foundations containing one, two and three joint sets is investigated in the case of punching failure. The effect of joints spacing is incorporated to the analyses using a dimensionless factor, named spacing ratio (SR). Different values for SR are selected and variation of the bearing capacity versus SR is monitored. Then, the magnitude of SR in which the bearing capacity does not change significantly, is determined. The findings show that for SR<30, increasing the SR results in decreasing the bearing capacity, while for SR>30, the joints spacing do not affect the bearing capacity, significantly. Hence, SR=30 can be used as a criterion for analysis of rock foundations either as an equivalent continuum or a discontinuous medium. Using this criterion will tend to greatly reduce the time required for the bearing capacity analysis of rock foundations.https://ceej.aut.ac.ir/article_388_d9fc5b73a8d78fad3d6dffe419384e70.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220پیوستگی میلگردهای فولادی و پلیمری در بتن های خودتراکمپیوستگی میلگردهای فولادی و پلیمری در بتن های خودتراکم10111638910.22060/ceej.2015.389FAMoosaMazloomAssistant Professor , Civil Engineering Department, Shahid Rajaee Teacher Training University, TehranKomeilMomeniPh.D. Student, School of Engineering Department, Gilan University, RashtJournal Article20120503In this research, numerous tests have been carried out for estimating the bond strength of steel and FRP bars with self- compacting and normal concrete specimens. The main experimental part of the research was concentrated on a pull out test. Two mix designs have been used for making self- compacting concrete and super plasticizer dosages of the two mixes were different. Therefore, the effect of super plasticizer dosage on bonding strength is also studied in this research.<br />Comparing the pull out test results on self- compacting and normal concrete showed that in all conditions, the bonding of steel bars was more than that of FRP bars., Moreover, self- compacting concrete containing higher dosages of super plasticizers had more bonding strength. The existing models were not exactly enough for estimating the bonding strength of FRP bars. Therefore ABAQUS software is used for modeling this phenomenon, and two models including two and three dimensional models were compared. The results of this section showed that the three dimensional modeling was better than the others for estimating the experimental results.In this research, numerous tests have been carried out for estimating the bond strength of steel and FRP bars with self- compacting and normal concrete specimens. The main experimental part of the research was concentrated on a pull out test. Two mix designs have been used for making self- compacting concrete and super plasticizer dosages of the two mixes were different. Therefore, the effect of super plasticizer dosage on bonding strength is also studied in this research.<br />Comparing the pull out test results on self- compacting and normal concrete showed that in all conditions, the bonding of steel bars was more than that of FRP bars., Moreover, self- compacting concrete containing higher dosages of super plasticizers had more bonding strength. The existing models were not exactly enough for estimating the bonding strength of FRP bars. Therefore ABAQUS software is used for modeling this phenomenon, and two models including two and three dimensional models were compared. The results of this section showed that the three dimensional modeling was better than the others for estimating the experimental results.https://ceej.aut.ac.ir/article_389_c86a7ee3d8ef0b551ed58e354a836f2b.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Seismic Vibration Control of Nonlinear Structures Using Semi-Active Tuned Mass DampersSeismic Vibration Control of Nonlinear Structures Using Semi-Active Tuned Mass Dampers11713139010.22060/ceej.2015.390FAMohtashamMohebbiAssistant Professor, Engineering Department, University of Mohaghegh ArdabiliHamedRasouliM.Sc. Student, Engineering Department, University of Mohaghegh ArdabiliSolmazMoradpourM.Sc. Student, Engineering Department, University of Mohaghegh ArdabiliJournal Article20120605In this paper, designing semi-active tuned mass damper (SATMD) for reducing the response of nonlinear frame structures under earthquake excitations has been studied. The semi- active characteristic of the control system has been achieved by modifying the damping in each time step. To determine the appropriate command signals for selecting the damping coefficient of SATMD, a semi-active control algorithm based on nonlinear instantaneous optimal control and Clipped Optimal Control concept has been developed. Also for optimal design of the control system, the design parameters have been determined by solving an optimization problem that minimizes the maximum response of the structure using genetic algorithm (GA). As numerical example, for an eight-storey nonlinear shear frame with bilinear hysteresis behavior under white noise excitation, SATMD has been designed. The results of numerical simulations show the capability of the proposed method for determination of control signal as well as the effectiveness of the SATMD mechanism in reducing the response of the nonlinear structures under earthquake excitation. In addition, comparing the performance of SATMD with those of passive and active tuned mass dampers shows that SATMD has worked better than passive tuned mass damper while active mass damper shows better performance than SATMDIn this paper, designing semi-active tuned mass damper (SATMD) for reducing the response of nonlinear frame structures under earthquake excitations has been studied. The semi- active characteristic of the control system has been achieved by modifying the damping in each time step. To determine the appropriate command signals for selecting the damping coefficient of SATMD, a semi-active control algorithm based on nonlinear instantaneous optimal control and Clipped Optimal Control concept has been developed. Also for optimal design of the control system, the design parameters have been determined by solving an optimization problem that minimizes the maximum response of the structure using genetic algorithm (GA). As numerical example, for an eight-storey nonlinear shear frame with bilinear hysteresis behavior under white noise excitation, SATMD has been designed. The results of numerical simulations show the capability of the proposed method for determination of control signal as well as the effectiveness of the SATMD mechanism in reducing the response of the nonlinear structures under earthquake excitation. In addition, comparing the performance of SATMD with those of passive and active tuned mass dampers shows that SATMD has worked better than passive tuned mass damper while active mass damper shows better performance than SATMDhttps://ceej.aut.ac.ir/article_390_a01a0380ca3c61428c26a231f0e49a09.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Effect of Plastic Fines on Undrained Resistance
of Anzali SandEffect of Plastic Fines on Undrained Resistance
of Anzali Sand13314139110.22060/ceej.2015.391FAMajidEbrahimiM.Sc. Student, Campus of the the Guilan University, IranAliGhorbaniAssistant Professor, Department of Engineering, Guilan University, IranYaserJafarianAssistant Professor, Geotechnical Engineering Research Center, International Institute of Earthquake EngineeringJournal Article20150530In this regard, plastic fines have been added to Anzali sand with diverse proportions and then triaxial monotonic tests have been implemented to find that how these fine contents can affect the sand undrained shear behaviour. All the prepared samples had the same initial dry density and were subjected to two different confining pressures. The results show that, in comparison to the clean sand, increasing the content of plastic fines from 0 to 30% results in a decrease in the undrained shear resistance of the samples, wherease this trend is reversed for the values of fine contents greater than 30%. In addition, the effect of plastic fines on the pore pressure generation was studied in the saturated sands. The results reveal that the specimens having up to 30% plastic fine contents generated larger values of pore water pressure than clean sand specimens. And for the larger amounts of fine contents, the excess pore water pressure decreased comparing to the clean sand.In this regard, plastic fines have been added to Anzali sand with diverse proportions and then triaxial monotonic tests have been implemented to find that how these fine contents can affect the sand undrained shear behaviour. All the prepared samples had the same initial dry density and were subjected to two different confining pressures. The results show that, in comparison to the clean sand, increasing the content of plastic fines from 0 to 30% results in a decrease in the undrained shear resistance of the samples, wherease this trend is reversed for the values of fine contents greater than 30%. In addition, the effect of plastic fines on the pore pressure generation was studied in the saturated sands. The results reveal that the specimens having up to 30% plastic fine contents generated larger values of pore water pressure than clean sand specimens. And for the larger amounts of fine contents, the excess pore water pressure decreased comparing to the clean sand.https://ceej.aut.ac.ir/article_391_5a4b25aaed25c2ee1b74de72dc03c14e.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220Experimental Investigation on Mechanical Properties of Concrete containing Nano Wollastonite and Modeling with GMDH-type Neural NetworksExperimental Investigation on Mechanical Properties of Concrete containing Nano Wollastonite and Modeling with GMDH-type Neural Networks14315639310.22060/ceej.2015.393FAMahmoudMiriAssistant professor, Civil Engineering Dept., University of Sistan and Baluchestan, Zahedan, IranHossienBeheshti NezhadPh.D. Student, Civil Engineering Dept., University of Sistan and Baluchestan, Zahedan, IranMaliheJafariM.Sc. Student, Civil Eng. Dept., Birjand Branch, Islamic Azad University, Birjand, IranJournal Article20120729Wollastonite is a natural and low cost material, which can be replaced by cement in concrete. In the present paper, the influence of Nano Wollastonite on mechanical and durability of concrete was investigated using the measurement of compressive and flexural strength and water penetration on concrete specimens after 3, 7, 28 and 60 days. The results show that flexural strength increase of 63%, compressive strength of 9% and water penetration resistance with around 50% by substitute of 10% Nano Wollastonite. GMDH-type neural networks were used for modeling of these concrete properties. The aim of such modeling is to make a model for predicting of compressive and flexural strength of concrete with the different percentage of Nano Wollastonite. The age and percent of Nano Wollastonite were used as an input variables. The results show that the outputs of neural network model have a good agreement with experimental data.Wollastonite is a natural and low cost material, which can be replaced by cement in concrete. In the present paper, the influence of Nano Wollastonite on mechanical and durability of concrete was investigated using the measurement of compressive and flexural strength and water penetration on concrete specimens after 3, 7, 28 and 60 days. The results show that flexural strength increase of 63%, compressive strength of 9% and water penetration resistance with around 50% by substitute of 10% Nano Wollastonite. GMDH-type neural networks were used for modeling of these concrete properties. The aim of such modeling is to make a model for predicting of compressive and flexural strength of concrete with the different percentage of Nano Wollastonite. The age and percent of Nano Wollastonite were used as an input variables. The results show that the outputs of neural network model have a good agreement with experimental data.https://ceej.aut.ac.ir/article_393_70c639df5e30bdee440e4cdf599fec2b.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220An experimental study on one of the all steel Buckling Restrained BraceAn experimental study on one of the all steel Buckling Restrained Brace15716439410.22060/ceej.2015.394FAFereydonArbabiProfessor, International Institute of Earthquake Engineering and seismology, Tehran, IranMoienTabarokM.Sc. Student, International Institute of Earthquake Engineering and seismology, Tehran, IranJournal Article20130121Bracing is one of the primary devices that induced for resisting earthquake and wind lateral loads. Initially, the system was simple but as the time passed, due to shortcomings and economical problems, the type of braces changed and the changes were followed by its own complexion and complications. <br />With better understanding of behavior and performance of the simple braces, the uses of these increased, but buckling was most problems in the braces. In 1973, buckling resisting braces (BRB) were introduced. In this version of braces, a steel tube prevents the buckling of axial members, which in turn leads to an increased in BRB forces. The aim of the present study was to investigate an all steel BRB with specific detailing in order to produce a uniform plastic region. Its advantages of use of this BRB are being lighter, ease of construction, core opening re-evaluation possibility after loading and use of single material.... To do so, some experimental processes on six specimens with 1:4 scales were made. The results indicated that if the required details are observed the brace would have proper behavior and high-energy absorption.Bracing is one of the primary devices that induced for resisting earthquake and wind lateral loads. Initially, the system was simple but as the time passed, due to shortcomings and economical problems, the type of braces changed and the changes were followed by its own complexion and complications. <br />With better understanding of behavior and performance of the simple braces, the uses of these increased, but buckling was most problems in the braces. In 1973, buckling resisting braces (BRB) were introduced. In this version of braces, a steel tube prevents the buckling of axial members, which in turn leads to an increased in BRB forces. The aim of the present study was to investigate an all steel BRB with specific detailing in order to produce a uniform plastic region. Its advantages of use of this BRB are being lighter, ease of construction, core opening re-evaluation possibility after loading and use of single material.... To do so, some experimental processes on six specimens with 1:4 scales were made. The results indicated that if the required details are observed the brace would have proper behavior and high-energy absorption.https://ceej.aut.ac.ir/article_394_28f0b864598a1291557bed248a998d4e.pdfAmirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X46220150220صلاح طیف طراحی آئین نامه 2800 ایران برای ساختگاههای نزدیک گسل
با استفاده از زلزله های ثبت شده با و بدون اثرات جهتصلاح طیف طراحی آئین نامه 2800 ایران برای ساختگاههای نزدیک گسل
با استفاده از زلزله های ثبت شده با و بدون اثرات جهت16518839510.22060/ceej.2015.395FAAHMADNICKNAMAssociate Professor, School of Civil Engineering, Iran University of Science and TechnologyEhsanYousefi DadrasPh.D. Candidate, School of Civil Engineering, Iran University of Science and TechnologyJournal Article20140423Many populated urban areas of Iran are threatened by near source problems; forward directivity effects and fling step, which may cause huge catastrophic. The major reason is that this country is surrounded by the two huge mountain chains, Alborz and Zagross. As an example, Tehran is a city faced around with four near active faults, Mosha, North, Ray, and Karaj faults, which are potentially hazardous. This is under the condition that the design response spectra [A*B(T)] in Iranian Standard No. 2800, which is established on the basis of ten percent chance in fifty years, does not illustratively account for the directivity effects for sites located at near sources. This article is intended to propose a technique to descriptively modify the far field response spectra taking into account such problems for sites 20 Km far away from the active faults. The proposed modification factors are developed based on a limited number of near source data with and without directivity effects (58 recorded data) using three attenuation relationships. The proposed coefficients for four site soil conditions are implemented to the existing far field design response spectra presented in the fourth version of the response spectra. A comparison is made with those of UBC-97 and ASCE-7-2005 corresponding to two seismicity cities in the United State aimed at understanding how to assess their differences. The recommended technique may be interpreted as a start for developing a series of design response spectra having the potentiality of more accurately accounting for the near source problems.Many populated urban areas of Iran are threatened by near source problems; forward directivity effects and fling step, which may cause huge catastrophic. The major reason is that this country is surrounded by the two huge mountain chains, Alborz and Zagross. As an example, Tehran is a city faced around with four near active faults, Mosha, North, Ray, and Karaj faults, which are potentially hazardous. This is under the condition that the design response spectra [A*B(T)] in Iranian Standard No. 2800, which is established on the basis of ten percent chance in fifty years, does not illustratively account for the directivity effects for sites located at near sources. This article is intended to propose a technique to descriptively modify the far field response spectra taking into account such problems for sites 20 Km far away from the active faults. The proposed modification factors are developed based on a limited number of near source data with and without directivity effects (58 recorded data) using three attenuation relationships. The proposed coefficients for four site soil conditions are implemented to the existing far field design response spectra presented in the fourth version of the response spectra. A comparison is made with those of UBC-97 and ASCE-7-2005 corresponding to two seismicity cities in the United State aimed at understanding how to assess their differences. The recommended technique may be interpreted as a start for developing a series of design response spectra having the potentiality of more accurately accounting for the near source problems.https://ceej.aut.ac.ir/article_395_1543843a4723ed2ab08e18053ae6dc5b.pdf